The demand for energy is on the rise across the world. At the same time, civilization's most reliable energy sources, fossil fuels, are essentially non-renewable and have become more scarce, have been identified as the main culprit in the rise of greenhouse gases and pollution in the earth's atmosphere, and have caused social and political unrest as a result of their location and control. Due to the worldwide and ever increasing energy demand and the world's reliance on non-renewable energy sources, research increasingly focuses on ways to produce energy or power through the use of alternative and renewable sources of energy. This research may also be spawned by an increased desire to provide energy for people living in remote locations around the world who now live without power.
Current forms of power production are generally considered to be inefficient. Power for the most part is generated by boiling water to steam. The pressure from the steam turns a turbine, which, in turn, turns a generator. Nuclear energy and coal are the two leading producers of power. Both nuclear and coal power plants operate at about 33% efficiency, meaning about 66% of the heat that is generated is discarded.
Certain types of direct drive device and generators have been developed to take advantage of low to moderate thermal differentials. For example, PCT International Patent Application Publication No. WO98/007962 discloses a direct drive method that uses stationary heat exchangers to heat and cool a working fluid to drive piston heads, crank shafts, camshafts and/or connecting rod technology in a manner similar to the internal combustion engine to generator power. Similarly, U.S. Pat. No. 4,283,915 discloses a thermal hydraulic engine that also utilizes stationary heat exchangers into and out of which hot and cold fluids are pumped in order to control the thermal expansion of the working fluid. Both PCT International Patent Application Publication No. WO98/007962 and U.S. Pat. No. 4,283,915 are incorporated herein by reference in their entirety as to their description of thermal expanding working fluids and the use of thermal differentials and working fluids to drive a power generating device.
Such devices may possibly be used to take advantage of wasted energy, for example, heated water from power plants or other sources, such as solar energy or geothermal collection devices, or to take advantage of any other sources of fluids that can have a low or moderate temperature differential.